Field of the Invention
The present invention relates to a radiation imaging system configured to apply radiation photography to a subject based on contents of an examination request, a method for controlling the radiation imaging system, and a program for causing a computer to execute the method for controlling the radiation imaging system.
Description of the Related Art
A conventionally known radiation imaging apparatus irradiates an object with radiation (for example, X-ray radiation), and detects an intensity distribution of the radiation having penetrated the object to capture a radiation image of the object. Such radiation imaging apparatuses are used mainly in the medical and industrial fields. In recent years, a technique for converting radiation having penetrated a subject into an electrical signal to acquire a radiation image as digital data has been widely employed.
For example, in the medical field, radiological medical examinations are performed on a routine basis. Generally in medical examinations using radiation (radiological medical examinations), medical doctors of each branch of medicine create an examination request sheet describing target imaging portions and image capturing methods, and a radiological technician performs the radiological medical examinations according to examination request sheets. Further, some hospitals have an in-house communications network that interconnects various medical apparatuses to facilitate standardization of patient data management. With such a networked environment, a radiation imaging system performs imaging operations in cooperation with a hospital information system (HIS), a radiological information system (RIS), an image server (picture archiving and communication system (PACS)), etc., where examination request sheets and imaging results thereof are transferred, stored and displayed in accordance with the DICOM (digital imaging and communications in medicine) standard.
In a hospital having the in-house communications network, the HIS issues an examination request instead of issuing an examination request sheet by medical doctors. In this case, in the RIS, the department of radiology receives the examination request from the HIS, and performs a radiological medical examination by using the radiation imaging system based on the received examination request.
Upon completion of the radiological medical examination, the radiation imaging system notifies the HIS and RIS of the completion of the examination, and outputs acquired images and examination information to the PACS for archiving. In some cases, the radiation imaging system also outputs the acquired images and examination information onto a display unit or a printer.
In the medical field, patients undergoing radiological medical examinations often require repeated imaging operations, and regulatory entities require that a record of such operations be kept for reference for a predetermined period of time. Therefore, it is convenient to store the patient information and image capturing methods for future use or reference. In relation to radiological medical examinations, Japanese Patent Application Laid-Open No. 2007-275117 discusses a technique for displaying a list of preregistered image capturing methods on a screen and extracting image capturing methods from the image capturing method list, for example, by specifying target imaging portions on a human body model, thus registering the image capturing methods described on the examination request sheet to an examination.
Since photographing conditions and image processing conditions differ according to target imaging portions, imaging orientations, imaging procedures, and radiation detectors used for image capture, a large number of image capturing methods are preregistered in the radiation imaging system. Therefore, an operation for searching for the image capturing methods described in the examination request in the entire list is very time-consuming. In this case, the method for extracting image capturing methods by specifying target imaging portions on a human body model discussed in Japanese Patent Application Laid-Open No. 2007-275117 has been considered to be very effective.
For example, in an examination aiming for observation of patient's medical care process, the method compares a newly captured image with an existing image (a previously captured image) for purposes of evaluating the progress in medical condition of the patient. In this case, to acquire an image suitable for medical care process observation, it is necessary to capture a new image under the same imaging parameters and image processing conditions by using the same radiation detector as the existing image subjected to comparison.
In some hospitals, a radiation imaging system is used, for example, for health examinations in the morning and for clinical examinations in the afternoon. In this case, since examination contents depend on the medical purpose, each time zone has a specific distribution tendency of frequency in use of image capturing methods. Therefore, it is highly desirable that image capturing methods usable for capturing a new image are improved and optimized.